Floor drainage

ABSTRACT

Formwork creates a grid for receiving a filler material which defines a floor or floor base with a water drainage outlet. The formwork comprises a plurality of first wall members ( 4, 12 ) extending from an outlet zone ( 6 ) or channel ( 16 ). A plurality of second wall members ( 10, 14 ) extend between the first wall members to define the grid, with cells formed between the first and second members. Each first wall member ( 4, 12 ) has a progressively increasing height to define a downward slope for directing water towards the outlet zone ( 6 ) or channel ( 16 ), and the height of the second wall members ( 10, 14 ) will match that of the first wall members at junctions therebetween.

This invention relates to floor drainage, and particularly to formwork for laying on a horizontal surface as the basis for a floor with a water drainage outlet. Such floors are useful in so-called wet rooms where there is a substantially smooth transition from the main floor to an area where a shower is located. The invention does though, have other applications, and can be used generally where floor drainage is required.

Wet rooms of the kind referred to above have become increasingly popular because they avoid disadvantages associated with conventional shower trays. By making a shower area part of the room, the room can seem larger and the effect can be aesthetically pleasing. Particularly, with no rim or edge having to be stepped over to enter the shower area, it becomes less difficult to access, and can be used by individuals in wheelchairs.

The present invention is directed at formwork which creates a grid for receiving a filler material which defines a floor or floor base. Formwork according to the invention is for laying on a horizontal surface as the basis for a floor with a water drainage outlet. The formwork comprises a plurality of first wall members extending from an outlet zone. A plurality of second wall members extend between the first wall members to define a grid with cells formed between the first and second members. Each first wall member has a progressively increasing height to define a downward slope for directing water towards the outlet zone, and the height of the second wall members will match that of the first wall members at junctions therebetween. Either or both of the first and second wall members may comprise substantially planar strips. However, it is preferred that either or both of the first and second wall members comprise strips with a three dimensional cross-section, such as a triangular cross-section to provide increased rigidity. In a particularly preferred embodiment, the strips have an inverted V-shaped cross-section with the apex located uppermost to define an edge at the upper surface of the grid.

Formwork according to the invention can be assembled as a single unit. However, it is preferred to provide it in the form of a plurality of discrete units, each unit comprising first and second wall members defining at least one cell. The units would be adapted to couple together with a suitable mechanism to form a continuous grid. This enables the formwork to be provided as a set of modules, enabling the formwork to be assembled on site, and adapted as appropriate to the surface on which it is to be installed. By providing the formwork as a set of modules, its delivery to a chosen site can be facilitated, particularly when that site does not have easy access.

Modular formwork according to the invention will normally be based on a core section comprising at least one unit defining the outlet zone, and a plurality of additional units for connecting to the periphery thereof. The core section itself will normally comprise a plurality of units, and the edges of the units in such modular formwork will usually be straight to facilitate their assembly and connection. Typically, the core section is square or rectangular, and can conveniently comprise four isosceles triangular units, of each of which unit the base of the triangle forms a straight edge of the core section and the other sides converge towards the outlet zone.

Formwork according to the invention can define a substantially continuous curved surface around and sloping inwardly towards the outlet zone. However, it can also be designed to form a plurality of inclined planar areas suitably oriented to direct water to the outlet zone. This design is particularly suited to modular formwork comprising a plurality of units. It can also facilitate the casting of a filler material in the cells of the grid to create the final surface.

Embodiments of the invention will now be described by way of example, and with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of a first embodiment of the invention;

FIG. 2 is a plan view of the embodiment of FIG. 1;

FIG. 3 is a perspective view of a second embodiment of the invention;

FIG. 4 shows the embodiment of FIG. 3 with an arrangement of additional units;

FIG. 5 illustrates how the core section and additional units can be connected together to create formwork according to third embodiment of the invention; and

FIG. 6 is a cross-sectional view taken on line A-A of FIG. 5.

The formwork shown in FIG. 1 is a substantially square plastics moulding in the form of an open network or grid within a square frame defined by straight walls 2. A plurality of substantially straight first wall members 4 radiate outwardly from an outlet zone 6, for water drainage. The wall members 4 define a plurality of segments around the outlet zone, and these segments are divided into cells 8 by a series of substantially concentric circular second wall members 10. At selected junctions 12 between first and second wall members, provision is made for fixing screws to secure the formwork in place on a substrate.

Each first wall member has a height which steadily increases at sections further from the outlet zone 6. The second wall members 8 are each of constant height, but that height is determined relative to the distance from the outlet zone 6. In this way, when placed on a flat horizontal substrate, the upper edges of the first and second wall members 4,8 define a continuous curved surface around the outlet zone in the form of a very flat inverted cone. When the cells defined by the members are filled, a continuous surface is formed from which water will naturally drain to the outlet zone.

FIG. 3 shows a second embodiment of the invention in which the grid forms substantially square cells between the first and second wall members 12,14. The overall shape of the formwork is square, and can be seen to be divided into four triangular sections. These are defined by diagonal wall members 16. While this formwork would normally be provided as a single component, the triangular sections can be provided separately before being brought together as shown. In this variant, the diagonal wall members 16 will of course be present on only one side of each triangular section.

Whereas in the embodiment of FIGS. 1 and 2 the upper edges of the first and second wall members defined a continuous slightly curved surface, in the embodiment of FIG. 3 the upper edges of the wall members 12,14 in each triangular section define a planar surface inclined towards the outlet zone 6, or towards drain channels to the outlet zone 6, which are defined by the diagonal wall members 16. Once again the first wall members 12 will be of steadily increasing height relative to the distance from the outlet zone 6, and each individual second wall member 14 will be of constant height. The diagonal wall members 16 will also be of varying height, but of course the slope defined by each diagonal wall member 14 will be different from that defined by the first wall members 4.

FIG. 4 shows the formwork of FIG. 3 in conjunction with a number of discrete separate units 18,20,22 ready for coupling thereto. FIG. 5 shows the same arrangement of units after they have been coupled together, which as can be seen, enables the formwork to define a quite irregular shape. Each separate unit will have its own first and second wall members having the height and height variations required to abut smoothly with those in adjacent units with which they are to be aligned. The result is the creation once again of four planar surfaces converging towards the outlet zone 6 or respective drainage channels (16). A drainage unit 24 is shown in FIGS. 4 and 5, at the outlet zone.

The discrete units 18,20 and 22 shown in FIGS. 4 and 5 are connected by means of a simple keying mechanism. Respective edges of each unit are provided with a slot 26 or key 28 respectively to hold the units together. Additionally, and as better shown in FIG. 6, an edge of one unit is formed with a slot 30 for receiving the edge or wall 32 of the adjacent unit to further secure one unit relative to the other.

In formwork according to the invention the respective wall members can comprise simple strips of material; normally plastics or metal, which can be moulded or fabricated. In preferred embodiments however, the first or the second wall members have a little more rigidity. They could be of I- or L-shaped cross-section but most preferred is an inverted V-shaped cross-section with the apex of the “V” at the upper edge. Particularly when the formwork is provided as a number of discrete units, by having this additional rigidity in either the first wall members or second wall members or both, the units are more resilient and easier to handle. An inverted V-section for the wall members also facilitates the casting of a filler material in the cells, as the cross-section of each cell is reducing towards its base.

The inverted V-section of the second wall members 14 is clearly shown in FIG. 6. FIG. 6 also illustrates the continuous incline created by the reducing height of the second wall members 14, and the slope formed by the visible first wall member 12, towards the drainage unit 24, which is not illustrated or described in detail. The view shows adjacent units in the background.

It will be appreciated that discrete units in modular formwork according to the invention can be combined around a core section to form a variety of different shapes. It will though, also be appreciated that formwork according to the invention provided as a single unit can be made any of a variety of shapes including square as illustrated in FIG. 1; rectangular, circular, ellipsoidal or any other polygonal shape.

When installing a floor using formwork according to the invention, the formwork is first placed and then secured on the base substrate, and in such a manner that the lower surface of the formwork is substantially horizontal. Once it is secured, a filler material such as a concrete mix is cast in the cells of the formwork using the usual techniques. Because each cell is relatively small, the filler material can cure with the required inclined surface being substantially continuous over and between adjacent cells. Where the formwork is located on a concrete screed, the screed outside the perimeter of the formwork is also brought up to the top of that perimeter to form a smooth transition with the filler material within the formwork. Once the filler material and any further screed has hardened, a flooring material can be fitted over the floor and the formwork to form a substantially continuous surface. The flooring material can be fitted substantially in the manner described in British Patent Specification No: 2 361 637. 

1. Formwork for laying on a surface as the basis for a floor with a water drainage outlet, which formwork comprises a plurality of first wall members extending from an outlet zone, each first wall member having a progressively increasing height to define a downward slope for directing water towards the outlet zone: and a plurality of second wall members extending between the first members to define a grid for receiving a filler material in cells formed between the first and second members.
 2. Formwork according to claim 1 wherein the first wall members and the second wall members comprise substantially planar strips.
 3. Formwork according to claim 1 wherein at least one of the first wall members and the second wall members comprise strips of three-dimensional cross-section.
 4. Formwork according to claim 3 wherein the strips have an inverted V-shaped cross-section.
 5. Formwork according to claim 1 comprising a plurality of discrete units each comprising first and second wall members defining at least one cell, and a mechanism for connecting the units to form a continuous said grid.
 6. Formwork according to claim 5 wherein each unit defines a plurality of cells.
 7. Formwork according to claim 5 including a core section comprising at least one unit defining the outlet zone and a plurality of additional units for connecting to the periphery thereof.
 8. Formwork according to claim 7 wherein the core section itself comprises a plurality of units defining the outlet zone.
 9. Formwork according to claim 7 wherein the core section and each additional unit has straight edges.
 10. Formwork according to claim 9 wherein the core section is square or rectangular.
 11. Formwork according to claim 10 wherein the core section comprises four isosceles triangular units of each of which unit the base of the triangle forms a straight edge of the core section and the other sides converge towards the outlet zone.
 12. Formwork according to claim 9 including at least one additional unit for extending around two adjacent edges.
 13. Formwork for laying on a surface as the basis for a floor with a water drainage outlet, which formwork comprises a plurality of first wall members extending from an outlet zone, each first wall member having a progressively increasing height to define a downward slop for directing water towards the outlet zone: and a plurality of second wall members extending between the first members to define a grid for receiving a filler material in cells formed between the first and second members, wherein the grid defines a plurality of inclined planar floor areas for directing water to the outlet zone.
 14. Formwork for laying on a surface as the basis for a floor with a water drainage outlet, which formwork comprises a plurality of first wall members extending from an outlet zone, each first wall member having a progressively increasing height to define a downward slop for directing water towards the outlet zone: and a plurality of second wall members extending between the first members to define a grid for receiving a filler material in cells formed between the first and second members, wherein the grid defines a substantially continuous curved surface around the outlet zone.
 15. Formwork according to claim 1 wherein the first and second wall members are substantially upright.
 16. Formwork according to claim 1 wherein at least some of the second wall members are curved.
 17. Formwork according to claim 16 wherein at least some of the second wall members form a circle.
 18. Formwork according to claim 1 wherein at least one of the first and second wall members is formed in metal or plastics material.
 19. A floor comprising formwork having a plurality of first wall members extending from an outlet zone, each first wall member having a progressively increasing height to define a downward slope for directing water towards the outlet zone: and a plurality of second wall members extending between the first members to define a grid with filler material in cells formed between the first and second members.
 20. A floor according to claim 19 with a covering thereon comprising one of tiles, a plastics material and a tanking membrane. 